Means of atomizing liquids



March 30, 1943. V ORHE.S 2,315,172

MEANS OF ATOMIZING LIQUIDS Filed Dec. 9, 1940 2 Sheets-Sheet 1VINVENTOR. 7555p TV March 30, 1943. J. T. VooRHQS 2 Sheets-Sheet 2 FiledDec. 9, 1940 INVENTOR. 75 7.' Vowel-151$ Patented Mar. 30, 1943 UNITEDres PTENT OFFICE 1, Claim.

This invention relates to oil burners especially adapted for use inpower plant installations, and particularly pertains to a means ofatomizing liquids.

In the operation of oil burners of the straight mechanical or pressuretype the oil burner atomizes by pressure only. It is of course requisitethat the oil shall be heated to reduce its viscosity to approximately150 S. S. U. or less, except when the normal viscosity of the oil issufficiently low such as is usually the case when an oil of 28 Be. or A.P. I. gravity or less is used. It is characteristic of oils having suchviscosity limits to atomize them under straight pressure. This places alimit on the oil burning capacity range of a burner having tips of anyselected size since oil must be delivered under a minimum pressuresufficient to produce proper atomization, after which the capacity canonly be increased by increasing the pressure. The formula expressingthis phenomena is that the quantity of oil which is atomized with agiven size tip varies as the square root of the pressure on the oil,thus in order to double the capacity of the fire without changing thetip it is necessary to multiply the pressure four times. It will berecognized that in varying the pressure the atomizing effect is directlyvaried in a straight pressure type oil burner. It is desirable tomaintain a constant atomizing effect throughout the entire range ofpressure while using a given size burner tip. It is the principal objectof the present invention, therefore, to provide a method and means ofatomizing fuel oil whereby pressure may be applied to the oil and it maybe atomized, and by which method the atomization will be maintaineduniformly throughout the range of capacity of the burner tip.

The present invention contemplates the provision of an oil burner havinga pressure pump for delivering liquid fuel under pressure to anatomizing nozzle from which it is ejected in an atomized spray, thestructure including a novel type of nozzle tip and means for permittinga surplus flow of the liquid fuel to return to the source of fuel supplywhile controlling the fuel pressure.

The invention is illustrated by way of example in the accompanyingdrawings, in which:

Figure 1 is a View in side elevation showing the general application ofthe present invention. Fig. 2 is an enlarged fragmentary View showingthe fuel supply conduits and a form of nozzle structure embodying theuse of a single nozzle tip. Fig. 3' is a view in transverse sectionthrough the nozzle tip as seen on the line 33 of Fig. 2. Fig. 4 is aView in transverse section through the nozzle tip as seen on the line 44of Fig. 2. Fig. 5 is a view in transverse section through the nozzle tipas seen on the line 5-5 of Fig. 2. Fig; 6 is an end view showing a formof the invention in which three nozzles are used.

Fig. '7 is a view in central longitudinal section as seen on the line1-1 of Fig. 6.

Fig. 8 is a view in transverse section showing the nozzle ducts as seenon the line 88 of Fig. 7.

Fig. 9 is a view in transverse section showing another form of inventionhaving a simplified nozzle.

Referring more particularly to the drawings, ill indicates aT-connection to which a conduit H is connected leading from a suitablesource of liquid fuel. A tubular feed pipe I2 is connected to thedischarge side of this conduit and leads to a nozzle head l3. Thisnozzle head is disposed at a desired position within a heat chamber andwithin which combustion of said fuel is to take place. The nozzle headl3 includes a cylindrical body member I4 which is of substantiallygreater diameter than the feed pipe I2. This body memher is formed witha central bore i5 at its outer end into which the feed pipe I2 isthreaded. Drilled longitudinally of the body member at opposite sides ofthe bore l5, and shown in Figs. 2 and 3 as being in diametricallyopposite sides of the body member, are longitudinal passageways it. theouter end of the bodymember [4 but do not extend entirely through thebody member. The innermost ends of these passageway are. closed bythreaded plugs H which may be removed when it is desired to clean theburner head. f At the forward end of the body member I4 is a counterborehaving a threaded inner end [B and a smooth cylindrical outer bore H).An inclined lip 20 is formed around the forward end of the outer bore toprovide a conical seat for a purpose to be hereinafter described. Thebore 19 is relatively large in diameter and is provided with radialducts 21 which form a fuel passageway between the longitudinalpassageway l6 and the bore 19. This construction is shown in Figs. 2 and3 particularly. At the ends of the passageways IG adjacent to the plugs,ll radial ducts 22 are provided and extend into the, bore l5. Thesepermit the liquid fuel to flow from the feed pipe I2 through the ducts22 and along the passageway It to the ducts 2| and then into the bore{9.

Extending through'the bore l9 and threaded into the bore'l8 of the bodymember M is an These passageways terminate adjacent to .hexagonalportion are greater than the dimensions of the bore l9 so that thehexagonal end of the tip projects beyond the endface 26 of the.

body l4. Its. back face, as shown at 21, is inwardly tapered and seatsagainst the tapered face 2|] in the end of the body member l4. As shownin Fig. 3 of the drawings, the cylindrical body of the main nozzle tip23 is formed with a pairxof diametrically disposed tangential ducts 28which v communicate with a, central cylindrical bore 29 within thecylindrical body 24 of the main nozzle j tip. The central cylindricalbore has an outer conical face 30 which communicates with a centralrestricted jet opening 3|. This jet opening occurs at the apexof thebore. The cylindrical portion12'4 of the main tip 23 is formed with athreadediend .which screws into the bore I8 of the body member M. Acontinuationof the central bore 29. of the main nozzle tip provides anenlarged smooth cylindrical bore length 32 terminating'in a threadedportion 33. The juncture .of the bores 29 and 32 is represented by atransverse shoulder 34. At points midway the length of the wall: sectioncircumscribing the bore portion '32 radial ducts 35 are formed. Theseducts, as shown in Fig. 4 of the drawings, establish communicationbetween a space 35 which occurs between the cylindrical portion of themain nozzle tip 23 and the bore section 32 and the central bore 29 ofthe main nozzle tip.

Mounted withinthe main nozzle tip 23 is an innernozzle tip 31. The innernozzle tip 31 comprises'a threaded base 38 having a reduced portion 39which causes anannular space to occur within the bore 29and'therearound. An annular groove 40 is formed in the outercircumference of the portion .39 of the inner nozzle and lies in theplane of the'ducts 35. Tangential ducts 4| extendinwardly fromv saidgroove through the wall of the inner nozzle and terminate in a centralwhirling chamber 420f the inner nozzle. The base member 33 oftheinnernozzle has'a shoulder which abuts against the shoulder 34within'the main nozzle tip. The inner nozzle is formed with a tubulartip portion 43 within which thebore' 42 occurs. This tubular tip has atapered end'conforming to the taper 35 of the outer noz-v zle. Thus, awhirling chamber 44 for the outer nozzle is formed between the innernozzle tip 43 and the walls 29 and 35 of the main nozzle tip. Aplurality of return ducts 45 extend longitudinally through the baseportion 38 of the inner nozzle tip and establish communication betweenthe whirling chamber 44 of the main nozzle and the open end of the bore33;; V bore 5 of the body member I4 is indicated at 46. This extensionis of reduced diameter and communicates with the threaded bore |8 of thebody member. A return pipe 41 telescopes through the feed pipe'IZ andprojects through the bore 46 with a tight slip fit. The central bore 42in the inner nozzle jet is fitted with a restricted discharge opening 46at its forward end. The opposite end of the bore is partially closedwitha threaded plug 49 which is formed with a central bleeder duct 50.therethroug'h. In the form of the invention shown in Fig. of. thedrawings a feed pipe I? and the return An extension of the pipe 41 arecarried on a burner head 5|, the end of which is formed with threefacets 52. These facets are disposed in inclination to the normal planeof the end of the burner body. Carried in each facet is a nozzlestructure as shown and described in Fig. 2'. The end of the feed pipe I2communicates with a distributing chamber 53 within the head 5|.Distributing passageways 54 lead diagonally from the chamber 53 andterminate near the forward end of the head 5|. A lateral passageway 55establishes communication between the passageways 54 and the annularspace l9. Return passageways 55 lead from the end of the bore l8 to achamber 51 which is in communication with the return pipe 41.

I n the form of the invention shown in Fig. 9 a modified form of theinvention is shown in which 3 main nozzle tips 58 are provided and arefed from a main passageway 59 through distributing ducts B0. The nozzletips 58 are formed with a central bore 6| which terminates at its outerendin a conical end portion 62 from whichla discharge orifice 63 leads.Extending through the side walls of the nozzle tip are radial ortangentially arranged ducts 64 which communicate with a circumscribingchamber v65.. The .chamber 65 is in communication with the distributingducts 60. The nozzle tips 58 are formed with an enlarged head portion66, similar to that disclosed in the other views of the drawings, thishead having a tapered shoulder 61 fitting in a tapered counterbore 68 ofthe chamber 65. A threaded bore 69 forms a continuation'of the chamber65 and re-. 'ceives' the portion of. the nozzle tip. In this particularform of the'invention a plug 10 is inserted into the nozzle tip bore Eland is held in position by a pin II. In the form of nozzle tipconstruction disclosed in Fig. 9, as vwell as the more complicatednozzle tips shown in the other figures of the drawings, it will berecognized that the entire nozzle tip structure is a separate unit,which may be quickly placed in position in the head of the burnerstructure or removed therefrom as a unit. Due to this arrangement noadjustment of th tips is necessary when or after they are installed. 1

In operation of the presentinvention and with the pump through the feedpipe l2 and along the outside of the return pipe 47. The fuel oil thenpasses through the ducts 22 in the nozzle head M to and through thelongitudinal passageways It. The fiow of fluid thencontinues through theradial passageways 2| to the annular space l9 which occurs around themain nozzle tip 23. The fluid then flows through the tangential jets 2ato the whirling chamber 44. Here it will be given a spinning actionas itpasses around the inner tip. It will be forced outwardly through the jetopening 3| in the 'end of themain nozzle. At

the same timea portion ofthe oil which is delivered to the annular spaceI9 will pass through the tangential ducts 4| and intothe central bore 42of the inner tip. This will cause a second jet of oil to be createdwhich is projected into the center of the first jet of oilasthe twojets. emanate from the jet opening 3| in the main nozzle. Surplus oilwhich does not pass through the constrictions formed by the innerjetopening 48 and the outer jet opening 3| will flowto the return pipe 4!throughthe return ducts 45 and 50. The

rate of return flow of the oil is controlled by a V valve 12. It will beseen that the nozzle structure creates two jets of commingling fluid.The tangential ducts 28 and 4| are arranged to cause both sprays to spinin the same direction. The object of the inner spinning spray is toinsure thorough atomization of a given quantity of oil without wideningthe spray angle and while acting upon a minimum volume of fuel oil.

Attention is directed to the fact that the main nozzle tip and the innernozzle tip are disposed concentrically and that the inner tip is nestedwithin the outer tip. The jet opening 3| of the main tip and the jetopening 48 of the inner tip are in communication with the whirlingchamber 44 of the outer nozzle and the chamber formed by the centralbore of the inner nozzle, respectively. A whirling action is imparted tothe oil delivered to both of said chambers and causes a jet of oil to beprojected outwardly through the discharge opening 48 of the inner tip,and then through the discharge opening 3| of the main tip. Thus,atomized oil is discharged from the opening 3| in the main tip, whichoil in reality is in two jets, an outer spray jet created by the oilfrom the whirling chamber 44 and an inner spray jet created within theinner nozzle. It has been found that the action of the inner spray jettends to prevent the widening of the spray angle as the amount of oildischarged through the final orifice 3| is reduced. In cases where theoil supply is reduced to create a minimum size fire it appears that ahollow space is formed in the main whirling chamber 44, and that thespray from the inner tip strikes this film of oil along the tapered face30 leading to the final discharge orifice 3| of the main tip. This actsto slow the film of oil down so that the centrifugal force created inspinning the oil in the chamber 14 will not be sufiicient to greatlywiden the spray angle. It will therefore be seen that as the valve isregulated the pressure within the nozzle head will be established, andthat this re ulation does not depend upon restricting the inflow of fueloil through the pipe l2. That flow of oil is established by theoperation of the fuel pump I0. By this arrangement, therefore, any givenvolume of oil is delivered to the nozzle while the proportion of oilatomized and discharged from the nozzle is controlled by regulation ofthe return valve 12. Attention is directed to the fact that the oilreturning from both nozzle tips will pass through the return pipe 41 andits pressure will be regulated by the return valve 12.

Referring to the form of the invention shown in Figs. 6 to 8, inclusive,the operation and control of the nozzle is the same as previouslydescribed with the exception that there are a plurality of nozzles towhich the fuel oil is simultaneously fed and from which the surplus oilis allowed to escape through the return pipe 41 as regulated by thevalve 12. The form of the invention shown in Fig. 9 functions in thesame manner save that there is no inner nozzle and no return feature.

It will thus be seen that the invention here disclosed provides a nozzlestructure in which a high ratio of pressure to fuel oil may be createdand regulated, and whereby thorough atomization may be brought about atall times over a capacity range of a particular nozzle while varying thenozzle capacity to meet the demand of the equipment with which it isused.

While I have shown the preferred method and means of atomizing a fueloil and controlling the volume of oil being atomized, it is to beunderstood that various changes might be made in the steps of the methodand the combination, construction and arrangement of parts by thoseskilled in the art without departing from the spirit of the invention asclaimed.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

In combination, a burner head including a cylindrical body member havinglongitudinal passageways therein closed .at opposite ends, a centralpassageway therethrough open at its opposite ends, the inner end of saidpassageway receiving a fluid supply pipe of relatively large diameter,the opposite end of said passageway being formed with a smoothcylindrical bore continuing with a threaded bore, said threaded borecommunicating with a length of passageway of reduced diameter, a returnpipe fitted within said length of passageway of reduced diameter andextending longitudinally of the supply pipe, said return pipe beingsuiiiciently less in diameter than the supply pipe as to form an annularpassageway between the pipes for the flow of liquid fuel, radialpassageways leading from said annular space to the longitudinalpassageways in the body member, radial passageways at the outer end ofsaid longitudinal passageways establishing communication between saidpassageways and the smooth cylindrical bore in the body member, a mainburner tip extending through said smooth cylindrical bore and beingscrewed into the threaded bore of the body member, the outer end of saidburner tip closing the outer end of the cylindrical bore, whereby anannular chamber will occur around the burner tip, a central cylindricalbore within the burner tip in substantially the same plane as that ofthe smooth cylindrical bore of the body member, the outer end of saidcentral cylindrical bore continuing in a frustoconical wall convergingoutwardly and centrally of the burner tip, a restricted dischargeopening at the apex of said wall section, tangential ducts through thewall of the burner tip establishing communication between thecylindrical bore within the body member and the cylindrical bore withinthe burner tip, an inner burner tip mounted within the bore of the outerburner tip and spaced from the walls thereof, said inner burner tiphaving means to close the cylindrical bore within the outer burner tipat the inner end thereof. the forward end of said inner burner tip beingfrusto-conical and spaced from the frusto-conical section of the bore ofthe inner burner tip, a relatively small discharge passage in the end ofthe inner burner tip in axial alignment with the discharge passage inthe outer burner tip, tangential ducts in the walls of the inner burnerstruc ture for delivering liquid to the central passageway thereof,ducts through the wall of the outer burner tip communicating with theannular bore in the body member and the last said tangential ducts tosupply oil to the inner burner tip and return ducts establishingcommunication between the interior of the inner burner tip and thereturn pipe and the interior of the outer burner tip and the returnpipe.

JOSEPH T. VOORHEIS.

